After I installed the newest update this week my S9 turned off and on again automatically, but it got stuck at the screen with the opened lock while turning back on. Had to hold the lock button to turn it off twice to succesfully turn on my phone. Right know everytime I turn off my phone this happens, so it gets stuck at the screen with the opened lock when it turns on again and I have to restart it twice. Help!!
It does sound like something has glitched @jorndebrouwer
If this was my phone I'd first back up and factory reset and if that didn't cure the issue then I'd turn to a Samsung Experience Store or Samsung Service Centre for assistance.
I wish you all the best with this situation.
Current Phone > Samsung Z Fold³ 5G.
I had exactly the same thing, I fixed it like this..
-- Goto settings / biometrics and security / secure startup
-- disable secure startup (do not require)
-- restart your phone (You'll be amazed how fast it starts)
-- go back to secure startup and re-enable it.
-- restart again and it should be OK